1. Field of the Invention
This invention relates to an automatic sheet processing device adapted to be mounted to the sheet outputting portion of an image forming apparatus such as a printing apparatus, a simple printing apparatus or other apparatus which outputs sheets (leaves such as cut sheets, cards and thin boards) one after another and used to receive the sheets successively output from the sheet outputting apparatus, automatically align the received sheets to one another, and then automatically bind the bundle of aligned sheets (by stapling or starching).
2. Description of the Prior Art
Automatic sheet processing devices of this type are effective to rationalize office work, and various devices of such type have already been proposed (for example, in Japanese Laid-open Patent Application No. 99548/1975, Japanese Laid-open Patent Application No. 119047/1978, etc.) and some of them have been put into practical use. Generally, however, these devices according to the prior art are bulky, complicated, expensive ones for use in combination with special, high-class sheet outputting apparatuses of specific types and cannot be used in ready combination with popular copying apparatuses, for example, and thus, they have lacked in versatility.
For example, the device disclosed in Japanese Laid-open Patent Application No. 119047/1978 is of a structure in which the copy finishing device (the sheet processing device) is contained in a copying apparatus. Further, this device is provided with an eccentric pushing device adapted to push the side surface and rear surface of sheets discharged into the tray of the sheet processing device and align the sheets, but is not provided with means for preventing floating up or curling of sheets. Furthermore, in this device, when the document binding operation is completed, the pamphlet is grasped by a jaw actuated by a compressed air cylinder and the pamphlet is discharged from the tray by pivoting of a transfer arm, and this leads to a very much complicated construction.
Also, in the device disclosed in Japanese Laid-open Patent Application No. 99548/1975 (corresponding British Patent No. 1,485,476), the sheet processing device including a staple device is very much complicated. That is, sheets are aligned in the upper tray and fall onto the lower tray, and are stapled in an obliquely standing state. The stapler moves to the bottom of the lower tray in response to the staple signal and binds the sheets. After the binding, the stapler moves along a shaft and opens the bottom of the lower tray. Accordingly, the bound bundle of sheets falls.
On the other hand, there are known several aligning means for aligning sheets in automatic sheet processing devices.